The present invention relates to a chromatography column which can more readily be packed and repacked than has previously been possible.
Frequently it is desirable to separate out one or more useful components from a fluid mixture that contains' other components which may not be useful or are less valuable. To accomplish this it is often necessary or desirable to fractionate such a fluid mixture to separate out the useful or desired components. This can be carried out by using liquid chromatography systems. Liquid chromatography may briefly be described as the fractionation of components of a mixture based on differences in the physical or chemical characteristics of the components. The various liquid chromatographic systems fractionate the components with a fractionation matrix. Some liquid chromatographic matrix systems fractionate the components of a mixture based upon physical parameters such as molecular weight. Still other liquid chromatographic systems will fractionate the components of a mixture based upon chemical criteria such as ionic charge, hydrophobicity, and the presence of certain chemical moieties such as antigenic determinants or lectin-binding sites on the components.
Chromatography systems of various sizes are used in both laboratory analysis operations and in industrial scale production operations in which separation steps such as separating out a fraction from human blood or separating out impurities from a pharmaceutical can be carried out in a large batch process.
The development of chromatography columns has aimed at providing ease of operation and various additional benefits which have particular commercial importance. These include: (a) the ability to be sterilized by autoclaving; (b) improved sanitation by virtue of design features giving less carryover of product from one batch to the next; (c) the ability to resist solvents; (d) material conformity to food grade FDA regulations; (e) an improved pressure tolerance; (f) lower cost; and (g) the potential for full or partial automation.
Traditionally, a chromatography column must be disassembled to reslurry and remove chromatography media in order to repack the chromatography column with fresh chromatography media or with different chromatography media specific for an application. This procedure has several problems. First, the time required to perform this operation is substantial, especially with large industrial columns, and results in lost productivity in a commercial operation. Second, the constant assembly and disassembly of the chromatography column creates excessive wear on the components and leads to a reduced life of the chromatography system. Third, mechanical lifting equipment and significant floor and head space are required. Finally, each time a chromatography column is disassembled there are increased opportunities for unwanted contaminants to be introduced into the column, which can subsequently contaminate the fluid mixture and fraction of interest.
Another problem associated with some types of chromatography columns is the inability to clean the flow path used to introduce chromatography media into the chromatography column while maintaining a barrier between the cleaning solution and the packed chromatography media.